Increasingly stringent legal regulations make it necessary to decrease as much as possible the raw exhaust gas emissions generated by the combustion of the air/fuel mixture in the respective cylinders of internal combustion engines. Also in use in internal combustion engines are exhaust gas post-treatment systems that convert into harmless substances those pollutant emissions that are produced during the combustion process of the air/fuel mixture in the cylinder. An exhaust gas catalytic converter that is located in the exhaust gas duct of the internal combustion engine is regularly used for this purpose. High efficiency for the conversion of the pollutant components by the exhaust gas catalytic converter can be guaranteed only when it has at least reached its activation temperature. The activation temperature of the exhaust gas catalytic converter, for example, is 300° C. Therefore, it is very important to bring the exhaust gas catalytic converter up to its activation temperature as soon as possible after a cold start of the internal combustion engine.
On one hand, the mass of air in the cylinders is increased for this purpose by increasing an idling speed, and the combustion efficiency of the air/fuel mixture is impaired at the same time by a late shift of the ignition angle. The exhaust gas coming out of the cylinders during the exhaust cycle thereby easily reaches a very high temperature and thus has sufficient thermal energy to heat up the exhaust gas catalytic converter quickly. Legal regulations in individual countries require that this heating up of the exhaust gas catalytic converter be monitored.
The use of a functional architecture based on torsional moment is common for the control of internal combustion engines, for which all requirements that can be formulated as torsional moment or efficiency are actually defined on the basis of these physical quantities. Thus results a clear and concise structure with integrated interfaces defined by torsional moments or efficiencies. A functional structure of this type based on torsional moment for the control of an internal combustion engine is, for example, known from the reference book “Handbuch Verbrennungsmotoren” (Internal Combustion Engines Manual), editors Richard von Bass Huysen/Fred Schäfer, 2nd edition, Vieweg Verlag, 2002, pages 554 to 557.
Furthermore, it is common for the control of internal combustion engines to dynamically model the dynamics of an intake duct of the internal combustion engine over which the cylinder takes in air by means of an intake manifold charging model. This makes it possible to easily and precisely estimate an actual air mass flow into the respective cylinder also during transient operation of the internal combustion engines on the basis of various measurement categories such as, for example, a degree of opening of a throttle valve. In addition, an intake manifold charging model of this type can also be inverted such that a degree of opening of the throttle valve is determined, depending on an air mass flow to be adjusted in the respective cylinders. An intake manifold charging model of this type is likewise known from the reference book mentioned above, “Handbuch Verbrennungsmotor” (Internal Combustion Engine Manual), 2nd edition, pages 557 to 559.
In addition, a dynamic intake manifold model for an internal combustion engine is also known from WO 97/35106. A functional structure based on torsional moment for the control of an internal combustion engine is known from DE 196 12 455 A1.